DSH cat Charly, 12 years

Palpable abdominal masses

With kind permission of Drs. David and Krützfeldt, Small Animal Clinic Frankenthal



The radiographs are of diagnostic quality; both lateral and VD views are slightly rotated.

Body condition score (BCS) 5/9.

The disc spaces T12-L3 are narrow and the endplates are deformed.

The abdominal detail is good. Both renal shadows are severely enlarged. The right renal shadow is 5.5 and the left 4 x the length of the vertebral body of L2 (normal: 1.9 – 3.2x the length of L2 vertebral body). The renal contours are smooth. Their shape is oval with loss of the characteristic indentation at the level of the renal hilus. The opacity is that of soft tissue. The renal enlargement causes a severe mass effect with displacement of the adjacent organs. The stomach contains a moderate amount of food and is cranially displaced; its caudal contour is concave. The intestinal tract is severely displaced ventrally. The small intestine is mostly empty and the colon contains formed faeces and gas. The other abdominal structures appear physiological.

Radiological diagnoses

  • Severe bilateral renomegaly
  • Degenerative disc disease T12-L3


Differential diagnoses in case of bilateral renomegaly with smooth surfaces, physiological shape and opacity include perirenal pseudocyst, diffuse, infiltrative neoplasia such as lymphoma and hydronephrosis.


On ultrasound a large amount of anechoic, subcapsular fluid surrounded both kidneys. This is compatible with perirenal pseudocyst (bilateral).

Perirenal pseudocyst describes a peri-renal, mostly subcapsular, fluid accumulation which usually represents a transudate. The cause is unknown. Often chronic renal disease is present though a causative effect has yet to be proven.

US image: with kind permission of the Small Animal Clinic Frankenthal